When we walk down Broadway in Manhattan, we sometimes forget that New York is virtually surrounded by water. In fact, the five boroughs have 578 miles of shoreline. If global warming ends up melting enough sea ice at the poles to cause the sea level to rise, New York City is in a world of trouble.

The only borough that’s on the mainland of the North American continent is the Bronx; all the rest are islands or parts of islands. As the region’s economy has been transformed from industrial to post-industrial, and as sewage treatment has ended the role of rivers as the repository for untreated sewage, residential, park and commercial development has gravitated to the shoreline. In the old days, we avoided waterfronts. Why do you think that Riverside Drive is a quarter of a mile from the Hudson River? It’s not really by the “side” of the river because as recently as a few decades ago, we dumped raw sewage directly into the Hudson. No one in his or her right mind would want to get very close to the Hudson River on a hot summer day. One benefit of federal water pollution laws is that sewage is now treated before it is released into our waterways, and rivers like the Hudson are clean enough today to live next to. The bike path along the river is now one of the great cycle paths of the city.

It is difficult to project how much the sea level will rise, but it’s definitely heading upward. Writing over a decade ago, in a prescient 1996 article in the Annals of the New York Academy of Sciences, Professor Rae Zimmerman of New York University’s Wagner School of Public Service estimated that the sea might rise by a half a foot by 2030. However, she recognized that the world would probably last longer than that and cited projections of sea-level rise that ranged from two and a half to three feet by the end of the 21st century.
Of course, we don’t need to wait for the end of the century to know what flooding can do. We already know the impact of a storm surge on the subway and on roads like the Bronx River, Hutchinson and Saw Mill River parkways. They become submerged and are often impassable in heavy rain. Sea-level rise will make these storm surges worse and will increase wear and tear on infrastructure.

Even if storms do not grow in intensity, as many experts on global warming believe will happen, the impact of storms will increase.

Transportation, schooling and production will be disrupted. Some of this disruption will simply be accepted. When the subways and highways are flooded, we will close them and either figure out a way around them or simply close the region down for business until the water goes away. When a blizzard comes, we all stay home and watch the snow fall, so I suppose we can always do the same thing when it rains.

Unless the damage is permanent and wrecks our homes, roads and subways we may do nothing to adapt to the impact of climate change on our infrastructure. If New Orleans could ignore its levees, why can’t New York simply turn its back to the sea and hope for the best?

This is not to say that New York is as vulnerable as New Orleans. But we are vulnerable. Some of our government agencies recognize this problem.

The Port Authority of New York and New Jersey has responded to the impact of flooding from nor’easters and constructed a dike and levee system that surrounds La Guardia airport. They have also undertaken floodgate construction beneath the Hudson River’s PATH commuter train tunnel. Of the 648 miles of subway track in New York City, 411 miles are underground. As Professor Zimmerman wrote back in 1996, “The system operates 343 pumping stations which remove an average of 15 million gallons of water a day accumulating from rainwater, high water tables and water main breaks.”

In addition to the subways, Zimmerman discuses a wide range of vulnerable infrastructure including solid waste transfer stations and sewage treatment plants that are located by the water.

The New York City Department of Environmental Protection (D.E.P.) and PlaNYC 2030 have been working on adaptation to climate change for a few years. In 2004, DEP began a Climate Change Task Force to work on adaptation to climate change. This was in part a response to an important study of the impact of climate change in this region that was completed back in 2001 and co-led by my Earth Institute and NASA colleague, Cynthia Rosenzweig, along with Rutgers Professor William D. Solecki. In its first progress report, PlaNYC announced the formation of a citywide intergovernmental Climate Change Adaptation Task Force to work on protecting our infrastructure from the risks posed by climate change.

Are we capable of adapting to climate change and investing in the infrastructure we need to prevent catastrophe? Well, to quote at least 20 well-known politicians, yes, and no.

If a huge and damaging flood comes suddenly and destroys billions of dollars of infrastructure, we are probably (excuse the pun) sunk. On the other hand if we get a few small, but painful, visible and easily understood examples of what may come, we might very well develop the political will to invest scarce capital in major infrastructure that could resist damage.

At its peak in World War II, nearly half the Gross National Product was spent by the government on national defense. Most healthy people contributed to the war effort. Many people who didn’t serve in the military worked in defense factories. While the invasion never got any closer than Hawaii, everyone could see the threat.

We also know how to invest in the future. Currently, New York City is nearing the end of a multidecade, multibillion-dollar project to build a third water tunnel to carry water from upstate. It is not a project designed to deal with a crisis of the moment, but to prevent a crisis in the future.
Hopefully, when we figure out what we need to build to prevent damage from sea level rise, we will make the necessary investment. Climate change is real and will require investment and sacrifice if we are to successfully adapt.

The right political leadership will make the threats posed by climate change just as clear now, and help form the political will to do something about it despite the cost. Hopefully, we haven’t forgotten how to act as a community.

I am grateful for the research assistance of Drew Foxman, a graduate student in Comparative and International Education at Columbia’s Teachers College.

Steve Cohen is the Executive Director of the Earth Institute and Director of the Master of Public Administration Program in Environmental Science and Policy at Columbia’s School of International and Public Affairs. Cohen has written numerous books on environmental policy and public management. More posts from his blog for The Observer are available here.